83 lines
2.2 KiB
C
83 lines
2.2 KiB
C
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/* Single precision version of nexttoward.c.
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Conversion to IEEE single float by Jakub Jelinek, jj@ultra.linux.cz. */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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/* IEEE functions
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* __nexttowardfd(x,y)
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* return the next machine floating-point number of x in the
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* direction toward y.
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* This is for machines which use different binary type for double and
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* long double conditionally, y is long double equal to double.
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* Special cases:
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*/
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#include <errno.h>
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#include <math.h>
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#include <math-barriers.h>
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#include <math_private.h>
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#include <math_ldbl_opt.h>
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#include <float.h>
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float __nldbl_nexttowardf(float x, double y);
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float __nldbl_nexttowardf(float x, double y)
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{
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int32_t hx,hy,ix,iy;
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uint32_t ly;
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GET_FLOAT_WORD(hx,x);
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EXTRACT_WORDS(hy,ly,y);
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ix = hx&0x7fffffff; /* |x| */
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iy = hy&0x7fffffff; /* |y| */
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if((ix>0x7f800000) || /* x is nan */
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((iy>=0x7ff00000)&&((iy-0x7ff00000)|ly)!=0)) /* y is nan */
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return x+y;
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if((double) x==y) return y; /* x=y, return y */
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if(ix==0) { /* x == 0 */
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float u;
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SET_FLOAT_WORD(x,(uint32_t)(hy&0x80000000)|1);/* return +-minsub*/
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u = math_opt_barrier (x);
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u = u * u;
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math_force_eval (u); /* raise underflow flag */
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return x;
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}
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if(hx>=0) { /* x > 0 */
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if(x > y) /* x -= ulp */
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hx -= 1;
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else /* x < y, x += ulp */
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hx += 1;
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} else { /* x < 0 */
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if(x < y) /* x -= ulp */
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hx -= 1;
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else /* x > y, x += ulp */
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hx += 1;
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}
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hy = hx&0x7f800000;
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if(hy>=0x7f800000) {
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float u = x+x; /* overflow */
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math_force_eval (u);
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__set_errno (ERANGE);
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}
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if(hy<0x00800000) {
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float u = x*x; /* underflow */
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math_force_eval (u); /* raise underflow flag */
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__set_errno (ERANGE);
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}
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SET_FLOAT_WORD(x,hx);
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return x;
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}
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#if LONG_DOUBLE_COMPAT(libm, GLIBC_2_1)
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compat_symbol (libm, __nldbl_nexttowardf, nexttowardf, GLIBC_2_1);
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#endif
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